/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: FunctionOneArg.java,v 1.2.4.1 2005/09/14 20:18:45 jeffsuttor Exp $
 */
package com.sun.org.apache.xpath.internal.functions;

import com.sun.org.apache.xalan.internal.res.XSLMessages;
import com.sun.org.apache.xpath.internal.Expression;
import com.sun.org.apache.xpath.internal.ExpressionOwner;
import com.sun.org.apache.xpath.internal.XPathVisitor;

/**
 * Base class for functions that accept one argument.
 *
 * @xsl.usage advanced
 */
public class FunctionOneArg extends Function implements ExpressionOwner {

  static final long serialVersionUID = -5180174180765609758L;

  /**
   * The first argument passed to the function (at index 0).
   *
   * @serial
   */
  Expression m_arg0;

  /**
   * Return the first argument passed to the function (at index 0).
   *
   * @return An expression that represents the first argument passed to the function.
   */
  public Expression getArg0() {
    return m_arg0;
  }

  /**
   * Set an argument expression for a function.  This method is called by the
   * XPath compiler.
   *
   * @param arg non-null expression that represents the argument.
   * @param argNum The argument number index.
   * @throws WrongNumberArgsException If the argNum parameter is greater than 0.
   */
  public void setArg(Expression arg, int argNum)
      throws WrongNumberArgsException {

    if (0 == argNum) {
      m_arg0 = arg;
      arg.exprSetParent(this);
    } else {
      reportWrongNumberArgs();
    }
  }

  /**
   * Check that the number of arguments passed to this function is correct.
   *
   * @param argNum The number of arguments that is being passed to the function.
   */
  public void checkNumberArgs(int argNum) throws WrongNumberArgsException {
    if (argNum != 1) {
      reportWrongNumberArgs();
    }
  }

  /**
   * Constructs and throws a WrongNumberArgException with the appropriate
   * message for this function object.
   */
  protected void reportWrongNumberArgs() throws WrongNumberArgsException {
    throw new WrongNumberArgsException(XSLMessages.createXPATHMessage("one", null));
  }

  /**
   * Tell if this expression or it's subexpressions can traverse outside
   * the current subtree.
   *
   * @return true if traversal outside the context node's subtree can occur.
   */
  public boolean canTraverseOutsideSubtree() {
    return m_arg0.canTraverseOutsideSubtree();
  }

  /**
   * This function is used to fixup variables from QNames to stack frame
   * indexes at stylesheet build time.
   *
   * @param vars List of QNames that correspond to variables.  This list should be searched
   * backwards for the first qualified name that corresponds to the variable reference qname.  The
   * position of the QName in the vector from the start of the vector will be its position in the
   * stack frame (but variables above the globalsTop value will need to be offset to the current
   * stack frame).
   */
  public void fixupVariables(java.util.Vector vars, int globalsSize) {
    if (null != m_arg0) {
      m_arg0.fixupVariables(vars, globalsSize);
    }
  }

  /**
   * @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner,
   * XPathVisitor)
   */
  public void callArgVisitors(XPathVisitor visitor) {
    if (null != m_arg0) {
      m_arg0.callVisitors(this, visitor);
    }
  }


  /**
   * @see ExpressionOwner#getExpression()
   */
  public Expression getExpression() {
    return m_arg0;
  }

  /**
   * @see ExpressionOwner#setExpression(Expression)
   */
  public void setExpression(Expression exp) {
    exp.exprSetParent(this);
    m_arg0 = exp;
  }

  /**
   * @see Expression#deepEquals(Expression)
   */
  public boolean deepEquals(Expression expr) {
    if (!super.deepEquals(expr)) {
      return false;
    }

    if (null != m_arg0) {
      if (null == ((FunctionOneArg) expr).m_arg0) {
        return false;
      }

      if (!m_arg0.deepEquals(((FunctionOneArg) expr).m_arg0)) {
        return false;
      }
    } else if (null != ((FunctionOneArg) expr).m_arg0) {
      return false;
    }

    return true;
  }


}
